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Flashcards in Respiratory Pathogens 1 Deck (50):
1

what is he degree of pathogenicity of a disease determined y

proteins it expresses and how effectively it cn integrate enviro info

2

what are some virulence mechanisms

bac adhesion
bac invasion
bac evsion host defnece
bac toxins

3

what is the cycle of bac infectivity

entry
attachment
multiplication
evasion of host defences
cause damage
release
spread

4

what are the components of bc adhesion

structure ligand
surface mol
receptors

5

what are some imp structure ligands

capsule (s progenies)
fimbriae (B pertusis)
cell wall (s aureus)
fibrils (s snguinis)

6

what are some imp surface mols receptors

keratinocytes
laryngeal epi cells
epi cells
platelets
salivary proteins

7

what can bac adhesion be

superificl/sytemic (metastasis)
extra or intracellular
access via general contact or injection

8

what are some examples of invasion

organism erodes tooth
organsim persisks in epi
org injected via arthropod

9

what are some common bac assc with caries and perio disease

caries - s mutans
peio - p gingivalis

10

lames disease from

borrelia burghdorferi

11

what does penetration of epithelium lead to

blood vessel end = blood circ
to phagocytic cells = both
lymphatic tissue end = accumulates in lymph nodes

12

what are some ways a bacteria can evade host defences

immunity at mucosal surfaces
destroy immune cells
interfere with inflam response
evade innate immunity
overcome acquires immune response

13

how can a bacteria have immunity at mucosal surfaces

production of glycosidases and Sialidases
(s cocci and veillonlela)
proteases
binding proteins

14

why is glycosylation of bac imp

imp for structure and function and resit to proteases

15

why is silica acid on IgA imp

imp for immunoglobulin function

16

what do proteases do

cleave hinge region of IgA normally protected by glycosylation
(s sanguines)

17

what do the binding proteins assc with mucosal surface immunity do

M family proteins
bind Fc region of iG
(s pyogeens and s aureus)

18

how does a bac interfere with cytokines

bac induce septic an ixic shock
TNF a, interferon and interleukins
myeloid, lymphoid and vasc respond to infection

19

what are cytokines

group of regulatory proteins key to immune response

20

what are endotoxins

gm -ve cell wall
LPS outer mem complex

21

what are LPS components

toxicity - lipid A
immunogenicity - polysacc

22

what does endotoxins induce

variety of inappropriate inflam responses that impair hosts response to pathogen

23

what does he outer mem of gm -ve bac consist of

assymetirc mem
LPS
peptidoglycan
lipoproteins
bind to receps on macrophages, b cells and other cells = cytokines

24

what is SIRS

systemic Inflammatory Response Syndrome

25

what are the ways of inflam cytokines being released

macrophages activated by LPS/endotixn or peptidoglycan

or

t cells activated by exotoxins

26

how is complement evaded

capsules
- prevent activation of C3 and C3B
- mask bound C3b

27

how is there evasion of phagocytic killing

PVL - s aureus
intracellular survival -- M TB
type 3 secretion systems

28

how is acquired immune repossess overcome

phase variation and antigenic variation

29

what is phase variation

switch between on and off forms of a gene
flagellin gene of salmonella
opacity genes of neisseria

30

what is antigenic variation

allows bac to change sequence of a gene
pilin genes of neisseira

31

what are the early symptoms of diphtheria

sore throat, low fever, swollen neck glands

32

what are the late stages of diphtheria

airway obstruction
breathing difficulty
shock

33

what are outbreaks of diphtheria assc with

unsanitary conditions
immunity gaps
vaccination fail

34

what is the product of diphtheria

toxin = acute inflammation and formation of pseudomembrane
- dead tissue
- fibrin
- polymorphs

35

what causes diphtheria

corynebacterium diphtheria
- gm +ve bacilli
- aerobic non motile
- toxin prod

36

how is diphtheria transmitted

direct contact droplets/skin, or indirect via contaminated object

37

explain some characteristics of corynebacterium diphtheria

sol 3 domain P's
endocytosed
proteolytic cleavage
catalytic domain
translocate domain

38

what is the treatment of diphtheria

inoculation with antitoxin
penicillin or erythromycin to slim bac

39

how is diphtheria prevented

active immunisation
diphtheria formal toxin
booster and multiple vaccine

40

what is whooping cough

highly contagious
life threatening

41

what causes whooping cough

bordetella pertussis
gm -ve cocci

42

what are the symptoms of whooping cough

severe cough
low/no fever at start
choking
nocturnal coughing
short breath
vomit

43

how does bordetella pertussis enter

via resp tract
attach to ciliated epi
mediated by filamentous hem agglutinin
pert actin

44

what is pertactin

outer mem protein
promotes attach to tracheal epi cells

45

what are the toxins assc with bordetetlla pertussis

pertussis toxin
adenylate cyclase
tracheal cytotoxin

46

what does tracheal cytotoxin do

kills ciliated cells and stimulates their extrusion from the mucosa

47

what is pathogenesis

growth on ciliate epi and toxin prod
- paralyse cilia tracheal cytotoxin
- stim inflam resp
- kill leucocytes

48

what does pertussis toxin do

disrupts cell function
increases mucus secretion
incapacitates phagocytes

49

what is the diagnosis and treatment of whooping cough

cough plate
swab pharyngeal walls
erythromycin
remove mucus
Ab therapy for secondary infections

50

how is whooping cough vaccinate

part of multiple vaccine
kill b pertussis
3 antigenic types